Power supply switching system



June 1.4, 1949. CHlNG-IH CHCJU 2,473,194

1 ?QYI ER'UPPLY SWITCHING SYSTEM Filed March 4, 194a INVENTOR. cums-m CHOU ATTORNEY Patented June 14, 1949 POWER SUPPLY SWITCHING SYSTEM Ching-ih Chou, West Webster, N. Y., assignorto Stromberg-Carlson Company, axcorporation of New York Application March 4, 1948, Serial N0.'-13,039

8 Claims. 1

This inventionrelates to a powersupply switching system, and more particularly to such a system for use in a radio receiver of the so-called three-way type, which is adapted to operate either from analternatingor. direct-current power line, or from batteries, usually self-contained.

A three-way radio receiver requires some kind of changeover switch having two positions, the first position providing for operation from the power line, and the second position for operation from batteries. As modern radio receivers are usually; constructed; a single position of such a switch permits operation from either alternatingor, direct-current power lines.

If an ordinary two-position switchis provided for. this purpose and it is arranged-to be manually operated by the user of the radio receiver, itis very likely that it will be improperly used due to ignorance or carelessness on the part of the operator. For example, if the linecord: of the radio receiver is connected to a'power outlet and the switch is in' the battery position, serious damage to the tubes or batteries may result. Even if the switch is of the two-pole type, so that, when'in the battery position, the power line is completely disconnected from the radio receiver, the receiver is very apt. to be operated from the batteries witha' needless waste of them,

although the user is underthe impression that power foroperation of the radio receiver is being secured from the power line because the line cord has been plugged into a power outlet.

Various arrangements have been proposed. in the past to overcome these difliculties. Insome ofthese arrangements, a receptacle isprovided on the backof the radio receiver into which the line-cord plug must be inserted during battery operation. In some cases, the insertion ofthe plug into this receptacle mechanically throws the power supply changeover switch of'the radio receiver. A difiiculty with this arrangement is that thezinsertion of the plug may be rather difiicult, because of the force-needed actually to throw the multiple switch required. In other prion-art arrangements, the insertion of the line-cord plug into the receptacle on the rear of the radio receiver so alters the electrical connections of the receiver as to render it adapted for operation from its self+contained batteries; With such an arrangement, the plug must be inserted'with the correct plurality and, therefore, it is" necessary to employ a plug of non-standard design toinsure its eorrect'positioning with respect to the receptacle; This is obviously disadvantageous both a.v changeover switch. which is actuated by the position of the. line cord'of the radio/receiver, and which, accordingly, requires no special effort or attention on the part of the operator when changing over frombattery to power-line operation or vice versa.

In accordancewith the present invention, there is provided,.in a radio receiver of the three-way type, a changeover switch whichis normally in the position for power-line operation when the line cord extends. fromthe rear of the radio receiver in alnormal manner for, this type of operation.. Whenthe. line cord. is stored within the radio receiver during battery operation, however, the changeover switch isso. arranged that it must be thrown to. the position for battery operation.

The above. and other objects and features of the'present. invention will be better understood by referring to the, accompanying drawing, in which .like reference numerals designate like components and in which:

Fig. 1 is a perspective view, partly in section, of a three-wayradio receiver embodying a power supply changeover switch in accordance with the present invention;

Fig. 2xis anend elevation, partly insection, of theradio receiver ofFig. 1; and

Fig. 3 isa sectional view. taken on the line 3-3 of Fig. 1;

Referring nowmore in detail to the drawing, there isrshown 1a radioreceiverhaving a cabinet or. housing I- which may have a carrying handle 2. Housing! is equipped-with a shelf 3 adapted to-receive and support the chassis 4 of the radio receiver, the controls 5 .of which may be accessible throughthefrontof housing I, as indicated in Fig. 2.

A portion of the space between the shelf 3 and the bottom member 6 of housing I .may be utilized for the. storage. of. abattery unit 1, connection to which'may be made with a conventional plug and cord arrangement as indicated at 8.

Chassis 4 is provided with a power supply changeover switchv 9, which is preferably of the rotary two-pole type with detent means, and which may be arranged'as shownlwiththe axis of its actuating shaft I arranged parallel to the longitudinal axis of chassis 4. Switch 9 is of the two-position type, a change from one position to the other requiring an approximately 90 rotation of shaft I0. Attached to shaft II] of switch 9 is an L-shaped handle II, preferably constructed of suitable insulating material, as for example a molded phenolic resin. Extending from the chassis 4 is a line cord I2 equipped with a conventional two-prong plug I3 adapted to be inserted into a standard power-line receptacle or outlet.

Line cord I2 passes through a hollow arm portion I4 of switch handle II, handle II being so positioned with respect to shaft ID that hollow arm portion I4 is substantially horizontal when switch 9 is in a position corresponding to powerline operation of the radio receiver. If desired, a helical spring I5 may be provided for maintaining switch handle II normally in the position shown in Fig. 2, one end of spring I5 being suitably anchored to chassis 4, as for example by being inserted into a hole I6 therein. Alternatively, means may be provided not only for biasing the switch, but also for retaining it in the position for battery operation until the back cover I8 is closed, but which thereupon releases the switch handle so that it shifts to the power-line operation position when the rear cover is again opened. While the cover is closed, the engagement of arm portion 2| with notch keeps the switch in the battery operation position.

Directly below switch handle II, there is provided in shelf 3 a slot II, this slot being adapted to receive line cord I2 when switch handle I I is in the position indicated in Figs. 1 and 3, that is, the position for battery operation. In this condition of operation, line cord I2 and plug I3 are stored in the space between shelf 3 and bottom 6 of housing I adjacent battery unit I.

Housing I is provided with a suitable back closure or cover I8, which is provided along its upper edge with suitable hinge means I9, so that it may be opened as indicated by the dashed line to permit access to be had to the components located within the housing I. If desired. spring means may be provided for holding back cover I8 in a normally closed position. Back cover I8 is provided with a suitable notch or opening 20. the area of which is such as comfortably to receive either end of switch handle II, but not large enough to receive line cord I2 at the same time.

In operation, let it first be assumed that power for the radio receiver is to be obtained from battery unit I. This condition of operation is illustrated in Figs. 1 and 3. In this case, the switch handle II is positioned with its hollow arm portion I4 vertically disposed and line cord I2 with its plug I3 are stored in the bottom portion of housing I. Rear cover I8 of housing I is closed and the end portion 2| of switch handle II protrudes into and substantially fills notch 20. If desired, end portion 2! may bear a designation, as for example the letter B as shown in Fig. 1, to indicate that the radio receiver is adjusted for battery operation.

Now let it be assumed that the operator desires to energize the radio receiver from the power line. To accomplish this, rear cover I8 of housing I is opened, and line cord I2 with its plug I3 is withdrawn from its storage space. Due to the action of spring I5, switch handle II is rotated in a clockwise direction as viewed in Fig. 1 until its hollow portion I4 is substantially horizontal as indicated in Fig. 2. Since the line cord I2 passes through this hollow portion, the line cord now extends from the rear of the radio receiver and the plug I3 at its end may be conveniently inserted in a power-line outlet. Rear cover l8 may now be closed. Notch 2D prevents interference due to either the line cord or the switch handle II when the rear cover assumes its closed position. It will be apparent that the radio receiver is now in condition for operation from the power line, and there is no possibility that power may inadvertently be drawn from the battery unit I.

To return to battery operation, rear closure I8 is again opened, switch handle II is rotated counterclockwise (as seen in Fig. 2) through approximately line cord. I2 and plu I3 are stored adjacent battery unit I, and cover I8 is closed, with end portion 2| of switch handle II protruding into and substantially filling notch 20. The receiver is now ready for battery operation.

While the provision of a biasing spring It on switch 9 is considered desirable, it is by no means essential. If this spring is omitted, the operator merely actuates switch arm II to the obvious and logical position for the type of operation desired. Since notch 20 in rear cover it is not large enough to receive both the end of switch handle II and line cord I2, there is no possibility that cord I2 will be brought out of the rear of the radio receiver when the end portion ZI is occupying this notch. Similarly, there is no likelihood that line cord I2 will be folded back on itself through notch 20 and stored when the hollow arm portion I4 of switch handle II is cocupying the notch. Thus the arrangement in accordance with the present invention is simple and foolproof in operation, and free from the likelihood of misuse.

While there has been described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In a radio receiver of the type adapted to operate from a plurality of power sources and having a line cord adapted to be connected to a first of said power sources external to said receiver, a space within said receiver for storing said line cord during operation from a second of said power sources, and a closure for said space, a changeover switch having first and second positions for adapting said receiver to operation respectively from said first and second power sources, and actuating means associated with said switch and said line cord, said actuating means engaging said closure in such a manner that said line cord extends from said receiver only if said switch is in said first position and said line cord occupies said storage space only if said switch is in said second position.

2. In a radio receiver of the type adapted to 0D- erate from a plurality of power sources and having a line cord adapted to be connected to a first of said power sources external to said receiver, a space within said receiver for storing said line cord during operation from a second of said power sources, and a closure for said space, a changeover switch having first and. second positions for adapting said receiver to operation respectively from said first and second power sources, and actuating means comprising an L- shaped member associated with said switch and said line cord, said actuating mean engaging a notch in said closure in such a manner that said line cord extends from said receiver only if said switch is in said first position and said line cord occupies said storage space only if said switch is in said second position.

3. In a radio receiver of the type adapted to operate from a plurality of power sources and havin a line cord adapted to be connected to a first of said power sources external to said re ceiver, a space within said receiver for storing said line cord during operation from a second of said power sources, and a closure for said space, a changeover switch having first and second positions for adapting said receiver to operation respectively from said first and second power sources, and actuating means comprising an L-shaped member having a hollow arm portion associated with said switch, said line cord passing through said hollow arm portion and said actuating means engaging said closure in such a manner that said line cord extends from said receiver only if said switch is in said first position and said line cord occupies said storage space only if said switch is in said second position.

In a radio receiver of the type adapted to operate from a plurality of power sources and having a line cord adapted to be connected to a first of said power sources external to said receiver, a space within said receiver for storin said line cord during operation from a second of said power sources, and a closure for said space, a rotary changeover switch having first and sec ond positions displaced approximately 90 for adapting said receiver to operation respectively from said first and second power sources, and an L-shaped handle for rotating said switch, said handle having a hollow arm portion through which said line cord passes and the arm portions of said handle selectively engaging a notch in said closure in such a manner that said line cord extends from said receiver only if said switch is in said first position and said line cord occupies said storage space only if said switch is in said second position.

5. In a radio receiver of the type adapted to operate selectively from first and second power sources, a changeover switch having first and second positions for adapting said receiver to operation respectively from said first and second power sources, a housing for said receiver having a rear opening and a removable closure therefor, an opening in said closure, and actuating means for said switch comprising a member having first and second arms adapted selectively to protrude into and to substantially fill said closure opening, said switch being in said first position when said first arm protrudes and in said second position when said second arm protrudes, whereby said closure must be displaced before said switch can be actuated.

6. In a radio receiver of the type adapted to operate selectively from first and second power sources, a rotary changeover switch having first and second positions displaced approximately for adapting said receiver to operation respectively from said first and second power sources, a housing for said receiver having a rear opening and a removable closure therefor, an opening in said closure, and actuating means for said switch comprising a member having first and second arms disposed in quadrature and adapted selectively to protrude into and to substantially fill said closure opening, said switch being in said first position when said first arm protrudes and in said second position when said second arm protrudes, whereby said closure must be displaced before said switch can be actuated.

'7. In a radio receiver of the type adapted to operate selectively from first and second power sources, a line cord adapted to be connected to said first power source external to said receiver, a changeover switch having first and second positions for adapting said receiver to operation respectively from said first and second power sources, a housing for said receiver having a rear opening and a removable closure therefor, an opening in said closure, and actuating means for said switch comprising a member having a first hollow arm portion and a second arm portion adapted selectively to protrude into and substantially fill said closure opening, said switch being in said first position when said first arm protrudes and in said second position when said second arm protrudes and said line cord passing through said hollow arm portion, whereby said closure must be displaced before said switch can be actuated and said hollow arm portion must occupy said opening to permit said line cord to extend outside of said closure.

8. In a radio receiver of the type to be adapted to operate selectively from first and second power sources, a line cord adapted to be connected to said first power source external to said receiver, a rotary changeover switch having first and second positions displaced approximately 90 for adapting said receiver to operation respectively from said first and second power sources, a housing for said receiver having a rear opening and a removable closure therefor, an opening in said closure, and actuating means for said switch comprising a member having a first hollow arm portion and a second arm portion disposed in quadrature and adapted selectively to protrude into and to substantially fill said closure opening, said switch being in said first position when said first arm protrudes and in said second position when said second arm protrudes and said line cord passing through said hollow arm portion, whereby said closure must be displaced before said switch can be actuated and said hollow arm portion must occupy said opening to permit said line cord to extend outside of said closure.

CHING-IH CHOU.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,121,421 Burt June 21, 1938 2,229,729 Emde Jan. 28, 1941 

